1. Field of the Invention
The present invention relates to a portable computer of a type such that a display formed of a liquid crystal or the like is swingably attached to a system body which includes a body unit, containing a processor, RAM, peripheral circuits, etc., and a keyboard module and the like.
2. Description of the Related Art
In general, a small-sized portable computer called a notebook type comprises a body unit, which contains therein a processor, RAM, peripheral circuits, etc., a keyboard module and the like, and besides, a swingable cover member which is furnished with a liquid crystal display (LCD). Prevailing liquid crystal displays use a back-lighting light source, and include a straight-pipe discharge lamp for use as a light source element, besides liquid crystal cells, segment substrate, polarizer plate, glass plate, etc. Inevitably, therefore, the cover member must be considerably thick all over.
The cover member, having the aforesaid parts therein, is swingably supported at its proximal end portion on the system body by means of a hinge mechanism. Since the hinge mechanism also requires a substantial thickness for a satisfactory strength, the respective thicknesses of those portions of the cover member, including the hinge mechanism, are substantially equal to or greater than the thickness of the display portion of the cover member.
In the computer of the type described above, a battery pack which contains a plurality of batteries is used as an operative or backup power source. In some cases, the batteries in the battery pack may be arranged in two or three rows, depending on the capacity required of the whole battery pack, capacity and size of each battery, etc.
The battery pack, containing the batteries in this manner, requires a substantial thickness and width, so that how to arrange the battery on the system body exerts a great influence on the reduction of the overall size of the computer, especially the thickness.
Referring now to FIGS. 49 and 50, therefore, two examples of the conventional arrangement of the battery pack on the system body will be described.
In FIG. 49, numeral 201 denotes a system body, which houses a body unit 203, which contains therein a processor, RAM, peripheral circuits, etc., a system control unit 203' including a keyboard module, track ball module, etc., and a battery pack 204. The system control unit 203' is situated substantially right over the body unit 203, while a hinge mechanism 206 for pivotally supporting a cover member 202 is located over the battery pack 204.
The battery pack 204, which is arranged side by side with the body unit 203, contains a plurality of (e.g., six) cylindrical batteries. In many cases, these batteries C1 and C2 are arranged in two rows, as shown in FIG. 49, in consideration of some restrictive conditions, including the size and capacity of each battery, length of the battery pack, etc. Naturally, therefore, the battery pack 204 has a height (thickness) not shorter than the diameter of each battery and a depth (in the horizontal direction of FIG. 49) twice the battery diameter or more. If the hinge mechanism 206 of the cover member 202 is situated right above the battery pack 204, as shown in FIG. 49, therefore, the overall thickness of the computer is D1+D2, where D1 and D2 are thicknesses of the system body 201 and the cover member 202, respectively.
With the recent technical innovation, the body unit 203 in the system body 201 and a liquid crystal in the cover member 202 have drastically been reduced in thickness. In consideration of the mechanical strength, on the other hand, the diameter of the hinge mechanism 206 cannot be reduced without limitation. Moreover, the diameter of the batteries C1 and C2 in the battery pack 204 cannot be freely restricted. If the battery diameter is reduced, then the overall capacity of the battery pack 204 will be lowered.
It may safely be said, therefore, that the thickness of the computer shown in FIG. 49 is settled substantially depending on the battery diameter (and hence the thickness of the battery pack 204) and the necessary strength of the hinge mechanism 206 for supporting the cover member 202. Thus, the computer of this type cannot be thinned all over without any restriction.
FIG. 50 shows another arrangement different from the one shown in FIG. 49. In FIGS. 49 and 50, like reference numerals refer to like or common elements. In the example shown in FIG. 50, the depth of the system body 201 is longer than the depth (L1) for the case of FIG. 49 by L2, that is, a little longer than that of the battery pack 204, and the pack 204 is housed in the marginal region. Accordingly, the hinge mechanism 206 which supports the cover member 202 cannot be situated right above the battery pack 204, so that the overall thickness (D3) of the computer can be restricted to a thickness, D1+D2, of FIG. 49 or less. Although the computer of FIG. 50 is thinner than the one shown in FIG. 49, however, it involves a drawback that its depth is extended by the margin (L2) corresponding to the depth of the battery pack.
In the conventional computer, moreover, the battery pack 204 is housed in the system body 201, and can be removed therefrom in some fashion if necessary. It cannot, however, be attached to and detached from the system body by simple operation.